Possibly as large as The Shard in London, Apollo asteroid 2017 VR12 passes just 3¾ lunar distances from Earth at 7:53am GMT on 7 March. For a few nights, this magnitude +12 space rock is a viable target for small backyard telescopes as it gallops through Coma Berenices and Virgo, passing just 0.8 degrees from Spica on the UK night of 7–8 March.
Five hundred-metre-wide asteroid 2017 CS passes just 1.9 million miles, or 7.9 lunar distances, from Earth on the afternoon of Monday 29 May 2017. For a few nights around this date, Northern Hemisphere observers with 6-inch and larger ‘scopes can see the asteroid gallop through the constellations of Canes Venatici, Boötes and Hercules at up to 14 degrees/day.
A small asteroid designated 2016 HO3 has been discovered in an orbit around the Sun that keeps it as a constant companion of Earth, and it will remain so for centuries to come. It is too distant to be considered a true satellite of our planet, but it is the best and most stable example to date of a near-Earth companion, or “quasi-satellite.”
Somewhat appropriately spooky for Halloween in recent radar images, 600 metre-wide near-Earth object 2015 TB145 dashes by our planet today. Now believed to be a dead comet that has shed its volatiles after numerous passes around the Sun, the object makes its closest approach to Earth at 5pm GMT. UK observers with clear skies may see it with modest telescopes in the early evening.
NASA scientists are tracking the upcoming Halloween flyby of asteroid 2015 TB145 with several optical observatories and the radar capabilities of the agency’s Deep Space Network at Goldstone, California. Only discovered sixteen days ago, the 400-metre-wide asteroid will fly past Earth at a safe distance slightly farther than the Moon’s orbit on 31 October at 5:05pm GMT.